A first of its kind study, published in Nature Cities, analysed what happens to clothes and other textiles after consumers no longer want them in Amsterdam, Austin, Berlin, Geneva, Luxembourg, Manchester, Melbourne, Oslo and Toronto.
Across most western cities from Melbourne to Manchester it found the same pattern of textile waste being exported, going to landfill or being dumped in the environment.
Global textiles waste each year weighs 92 million tonnes and this could double by 2030.
Charity shops handle a large amount of used clothes, but the study found because many are poor quality and there's little financial benefit to manage them locally, charities trade some valuable items and discard or export the rest.
In Melbourne, charities export high-quality, often vintage, second-hand clothes to Europe, forcing the city’s independent resale businesses to import similar apparel back from Europe or the United States.
But overall, charities and collectors have been reporting the plummeting quality of garments over the past 15 to 20 years, decreasing resale potential.
Study co-author Dr Yassie Samie, from RMIT University, said local governments and charities need to coordinate more to manage textile waste.
“We're used to charities doing the heavy lifting, but they’ve been unable to fully handle the volume of donated clothes for a long time now,” Samie said.
“Charities are driven by social welfare values and need to raise funds for their programs.
“However, their operations are ill-equipped to deal with the volume of used textiles that need to be reused and recycled.
“Given the role of charities within communities, it's essential they expand beyond direct resale in second-hand shops and explore other business models, such as swapping and repair centres.”
Overconsumption and oversupply were the main drivers of the cities’ textile waste, causing the export of between 33% (Australia) and 97% (Norway) of donated clothes.